FOSSIL FLORA OF THE STAFFORDSHIRE COAL FIELDS. 



77 





from to 19 feet 







, 2 to 9 „ 







, 3 to 12 „ 







, 5 to 30 „ 



■ Bottom Gubbin 





, 3 to 10 „ 

 , 18 to 50 ,. 

 , 2 to 4 „ 

 , 16 to 50 „ 

 , 2 to 9 „ 

 , 10 to 14 „ 

 , 4 to 7 „ 

 , 6 to 15 „ 

 , 2 to 3 „ 



s ironstone 



about 50 feet. 



30. Intermediate measures, sometimes wanting 



31. (I. 12) Rough Hills White ironstone (occasionally) 



32. (XXII.) Bottom coal ..... 



33. Intermediate measures ..... 



34. (I. 13) Gubbin and Balls ironstone, sometimes called the Great or 



35. Intermediate measures ..... 



36. (XXIII.) Singing, or Mealy Grey coal (occasionally) 



37. Intermediate measures ..... 



38. (I. 14) Blue Flats ironstone .... 



39. Intermediate measures ..... 



40. (I. 15) Silver Threads ironstone .... 



41. Intermediate measures ..... 



42. (I. 16) Diamonds ironstone .... 



43. Lowest measures, -maximum thickness known below the Diamonds ironstone 



It must be mentioned, as pointed out by its compiler, that the whole section does 

 not occur in any one point of the coal field, some parts of the section being absent 

 in one area and present in another, and at no one point are all these beds to be found. 

 The total estimated thickness of the Westphalian Series in the northern division 

 of the South Staffordshire Coal Field is about 2000 feet, and in the southern portion 

 between 500 and 600 feet. # This is brought about by the splitting up of the 

 Thick coal, which attains a thickness of 30 feet in the southern area, into eight or nine 

 seams, which, as traced into the northern division, become more and more separated 

 by an increasing thickness of the intermediate measures. 



The whole extent of the coal field as at present known is about 149 square miles.t 



Very little has been published on the fossil plants of the Westphalian Series of 

 South Staffordshire, the only notes known to me being that by Hooker in his paper, 

 '" On the Vegetation of the Carboniferous Period, as compared with that of the Present 

 Day" ; J a short paper by Mr B. Smith, § in which he figures a Lepidodendron stem which 

 may possibly be the Lepidodendron distans Lesqx. ; and a " Note on the Occurrence of 

 Whittleseya elegans Newb. in Britain," by Mr H. Hamshaw Thomas. || In addition 

 to these are the three papers by myself : that on the fossil plants collected during the 

 sinking of the shaft of the Hamstead Colliery, Great Barr, near Birmingham, to which 

 reference has already been made ; the description of the fructification of Neuropteris 

 heterophylla Brongt.;1I and the description of the microsporangia of Sphenopteris 

 Honinghausi Brongt.** 



From the northern portion of the coal field the plant records have not been so 

 fully worked out as in the southern area. 



Since beginning the study of the fossil plants of the South Staffordshire Coal 



* Gibson, The Geology of Goal and Goal Mining, Arnold's Geological Series, 1908, p. 184. 



t Gibson, loc. cit., p. 149. 



J Mem. Geol. Survey of Great Britain, vol. ii. part ii. p. 387, 1848. 



§ Geological Mag., dec. v., vol. ii. p. 208, 1905. 



|| Palaeobotanische Zeitschrift, vol. i. part i., Nov. 1912, p. 46 ; text-figs. 1, 2. 



IT Trans. Roy. Soc. London, series B, vol. cxcvii. pp. 1-5, pi., 1904. 



** Trans. Roy. Soc. London, series B, vol. cxcviii. pp. 413-445, pis. xxv.-xxviii., 1906. 



